Convert 146 calories to kilojoules need to know ASAP

A gold nugget has a volume of 4.35cm and a mass of 84.96g. What is its density?

Minchanka [31]

Density equal mass/volume
so you would have 84.96/4.35= 19.5310345

i hope i remembered this right

3 0

4 years ago

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Which of the clouds shown would indicate a possible future rain storm?

inn [45]

wheres the clouds?? i need a picture.

7 0

3 years ago

Describe what subatomic particle is involved in light emission.

KiRa [710]

Answer:

Option C= light is emitted as electron falls from the excited state to the ground state releasing a photon.

Explanation:

Electrons are responsible for the production of colored light.

Electron:

The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.

Symbol= e-

Mass= 9.10938356×10⁻³¹ Kg

It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.

How electrons produce the colored light:

Excitation:

When the energy is provided to the atom the electrons by absorbing the energy jump to the higher energy levels. This process is called excitation. The amount of energy absorbed by the electron is exactly equal to the energy difference of orbits.

De-excitation:

When the excited electron fall back to the lower energy levels the energy is released in the form of radiations. this energy is exactly equal to the energy difference between the orbits. The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum.

8 0

3 years ago

Consider the reaction 4HCl(g) + O2(g)2H2O(g) + 2Cl2(g) Using standard thermodynamic data at 298K, calculate the entropy change f

Ulleksa [173]

<u>Answer:</u> The value of $\Delta S^o$ for the surrounding when given amount of HCl gas is reacted is 73.21 J/K

<u>Explanation:</u>

Entropy change is defined as the difference in entropy of all the product and the reactants each multiplied with their respective number of moles.

The equation used to calculate entropy change is of a reaction is:

$\Delta S^o_{rxn}=\sum [n\times \Delta S^o_{(product)}]-\sum [n\times \Delta S^o_{(reactant)}]$

For the given chemical reaction:

$4HCl(g)+O_2(g)\rightarrow 2H_2O(g)+2Cl_2(g)$

The equation for the entropy change of the above reaction is:

$\Delta S^o_{rxn}=[(2\times \Delta S^o_{(Cl_2(g))})+(2\times \Delta S^o_{(H_2O(g))})]-[(4\times \Delta S^o_{(HCl(g))})+(1\times \Delta S^o_{(O_2(g))})]$

We are given:

$\Delta S^o_{(O_2(g))}=205.14J/K.mol\\\Delta So_{(HCl(g))}=186.91J/K.mol\\\Delta S^o_{(Cl_2(g))}=223.07J/K.mol\\\Delta S^o_{(H_2O(g))}=188.82J/K.mol$

Putting values in above equation, we get:

$\Delta S^o_{rxn}=[(2\times (223.07))+(2\times (188.82))]-[(4\times (186.91))+(1\times (205.14))]\\\\\Delta S^o_{rxn}=-129J/K$

Entropy change of the surrounding = - (Entropy change of the system) = -(-129) J/K = 129 J/K

We are given:

Moles of HCl gas reacted = 2.27 moles

By Stoichiometry of the reaction:

When 4 mole of HCl gas is reacted, the entropy change of the surrounding will be 129 J/K

So, when 2.27 moles of HCl gas is reacted, the entropy change of the surrounding will be = $\frac{129}{4}\times 2.27=73.21J/K$

Hence, the value of $\Delta S^o$ for the surrounding when given amount of HCl gas is reacted is 73.21 J/K

3 0

3 years ago

HURRY PLEASE In Maglev trains, fields exist between objects that are not in contact but can interact at a distance.

Irina-Kira [14]

True

Step by step explanation:

8 0

3 years ago

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